In the real world you are not going to have a calculator on you 24/7. Nor will you have a pencil or paper to do longhand. You need to know how to accurately estimate your answers in order to be successful.
Your blood circulates a total of 128 times a hour, or 3 times a minute.
-hope this helps
@FauxGeoDuck
X= -8/5y+16
y= -5/8x+10
you didnt say if the equation was "5x+8y=80" not sure if your adding or subtracting or adding but if your adding then this is correct :)